Most conventional power generation involves engines and/or motors. However, these technologies generally require combustible material (e.g., fuel, oil and/or coal) and expensive equipment (e.g., in terms of purchase price and maintenance costs). In addition, such material and equipment may consume a lot of space, requiring use of a large amount of ground area or real estate and driving up costs. Furthermore, these technologies may cause air and noise pollution and global warming. As a result, there is a need for more efficient and more reliable technologies for propelling vehicles and producing energy and/or electricity.
In conventional jet engines, air is compressed and slowed down by compressors, then mixed with fuel before entering a combustion chamber. The hot products of the combustion reaction then drive turbines, which have a common axis with the compressors. The hot products converge through a nozzle and accelerate out of the nozzle, thereby producing a forward-moving force. The net thrust of a jet engine is a result of pressure and momentum changes within the engine. Some of these changes produce forward forces, and some produce rearward or backward forces. The major rearward forces are due to the energy used to drive the turbines. Therefore, a fraction of the energy is left for jet engine thrust.
Pulsed jet engines, pulse detonation engines, and other similar types of engines have the simplicity and efficiency of combustion engines, at least in principle. Such engines have drawn attention over the last 70 years. Generally, in conventional pulsed engines and detonation engines, one pipe extends from the combustion chamber, which causes a recoiled shock wave when the fuel is detonated.
Pulsed jet engines are used today in drone aircraft, flying control line mode aircraft, radio-controlled aircraft, fog generators, and industrial drying and home heating equipment. The pulse detonation engine (PDE) marks a new approach towards non-continuous jet engines and promises higher fuel efficiency compared to turbofan jet engines, at least at very high speeds. Currently, Pratt & Whitney and General Electric have active pulse detonation engine research programs. Most pulse detonation engine research programs use pulsed jet engines for testing ideas early in the design phase. Boeing has a proprietary pulse jet engine technology called Pulse Ejector Thrust Augmenter (PETA). These engines are relatively difficult to integrate into commercial manned aircraft designs because of noise and vibration, although they excel on smaller-scale unmanned vehicles. Although pulse detonation engines have been considered for propulsion for over 70 years, practical pulse detonation engines have yet not been put into high volume production.
Generally, turbine engines have been used to propel vehicles (e.g., jets) and to generate industrial electrical power and central power. Typically, a turbine engine includes a compressor, a combustor, and a turbine in a sequential arrangement. Influent air is compressed to a high pressure in the compressor and is fed at a high speed and pressure into the combustor, where the air is mixed with a fuel and combusted to produce a hot, pressurized stream of gas that is passed into the turbine section, where the gas expands and drives a turbine. The turbine converts the energy (e.g., entropy and/or enthalpy) of the gas into mechanical work that drives the compressor and optionally other devices coupled to the gas turbine.
Although recent technology advancements have enabled the use of smaller, lighter gas turbines that are more efficient and less polluting than other engine types (e.g., combustion engines), the efficiency of gas turbines can be improved. For example, conventional natural gas-fired turbine generators convert only between 25 and 35 percent of the natural gas heating value to useable electricity. In addition, conventional engines carry a heavy load of fuel and oxidizers. Conventional engines general require specific types of fuel. Also, the combustion chamber and joints to the rotating arms in conventional rotating pulse engines may become very hot.
Furthermore, conventional turbines for hydro power, such as Pelton wheels, may be used to generate power and/or thrust. FIG. 1A shows a conventional Pelton wheel 100 for a turbine engine. The Pelton wheel 100 of FIG. 1A includes a rim 101, a plurality of spokes 150 that connect a central axis or shaft 120, and a plurality of buckets 102 on the rim 101. The central axis or shaft may be connected to sprocket or axle holders 140. Fluid (F) dispensed from a pipe 110 contacts the plurality of buckets 102 to spin the central axle or shaft 120 of the wheel 100, transferring the mechanical energy to and the wheel 100 and the axle or shaft 120 to generate power and/or thrust.
FIG. 1B shows a conventional bucket 102 of the Pelton wheel of FIG. 1A. The bucket 102 has a back portion 115 that attaches the bucket 102 to the rim 101 of FIG. 1A. The bucket 102 also has a front portion 116 that collects or receives the fluid. The front portion 116 of the bucket 102 has a curved bottom c-c. As shown in FIG. 1B, the bottom c-c include two curves that meet in an apex d. However, a high-speed stream of fluid shooting out from a nozzle (e.g., 112 in FIG. 1A) in a radial direction may not be the most effective or efficient use of conventional Pelton wheels. Thus, a need exists for more efficient and/or more adaptable turbine technologies for propelling vehicles and producing energy and/or electricity.
Typically, a propeller spinning in air or water may be pushed or pulled in one direction depending on the rotation direction and angle of the blade(s) 201a-b on an axle 202, as shown in FIG. 2A. A “T” shaped polyvinyl chloride (PVC) or metal pipe 203, 204 as shown in FIG. 2B may be referred to as a transporter because air or water may be expelled outward when the T-shaped pipe spins in either direction. A self-amplifying chain reaction may occur when the pressure of the fluid inside the transporter forces fluid to exit the transporter in a particular direction (see, e.g., U.S. patent application Ser. No. 15/227,846, filed on Aug. 3, 2016.
Generally, net thrust is the sum of a forward force and a rearward force (see, e.g., Aircraft Gas Turbine Engine Technology, Irwin E. Treager, 3rd edition). FIG. 2C shows ground thrust, forward thrust 210 and rearward thrust 220 of an axial-flow jet engine 200A having a compressor 230, a diffuser 240, a combustion chamber 250, a turbine 260, a tail pipe 270 and nozzle 280. The contribution of each component towards the forward and rearward forces is listed in Table 1 below (see, Aircraft Gas Turbine Engine Technology, Irwin E. Treager, 3rd edition, pg. 144-145).
ForwardRearwardCompressor=19,100Diffuser=2650Combustion chambers=32,000Turbine=−39,250Exhaust duct=3750Exhaust nozzle=−627057,500−45,520−45,52011,980
As shown in Table 1, a significant amount of rearward force or thrust 220 is contributed to the turbine 160. A net thrust of 11,980 lbs. is produced, which is a fraction of the kinetic energy consumed by the turbine. Thus, replacing the conventional turbine with a more efficient engine will advantageously increase the proportion of forward force or thrust (and thus the net thrust) in various types of engines, which in turn will increase the speed of an aircraft equipped with such an engine.
Generally, conventional turbines operate in a range of around or about 10,000 RPM, creating a relatively strong centrifugal field or force. For example, FIGS. 2D-F are diagrams showing various conventional jet engines and gas turbines. FIG. 2D shows a conventional jet engine 200B having an air inlet 220, a compressor 230, a combustion chamber 240, a turbine 250, and a nozzle 260 that expels the exhaust 290. Intake air 225 enters the air inlet 220, passes through the compressor 230, and is expanded in the combustion chamber 240. The expanding gas turns the turbine 250, and exhaust exits through the nozzle 270. Typically, the jet engine 200B has a cold section 211 and a hot section 212. The cold section 211 includes the air inlet 220 and the compressor 230. The hot section 212 includes the combustion chamber 240, the turbine 250, and the nozzle 260. FIG. 2E shows another conventional jet/engine 200C, similar to the engines 200A and 200B shown in FIGS. 2C-D. The conventional jet/engine 200D includes a compressor 221, a shaft 222, a combustion chamber 223, a turbine 224, and a nozzle 225. The compressor 221 may include a centrifugal impeller, as shown in FIG. 2E.
Furthermore, FIG. 2F shows a conventional gas engine 200F that includes an intake valve or inlet 220 for intake of fuel and air 226, a shaft 222, a compressor 232, a combustion chamber 234, a turbine 236, and an exhaust valve 238, through which exhaust 239 is released into the atmosphere.
This “Discussion of the Background” section is provided for background information only. The statements in this “Discussion of the Background” are not an admission that the subject matter disclosed in this “Discussion of the Background” section constitutes prior art to the present disclosure, and no part of this “Discussion of the Background” section may be used as an admission that any part of this application, including this “Discussion of the Background” section, constitutes prior art to the present disclosure.